Light emitting diode and light module having same

ABSTRACT

An LED includes an LED chip, a first package configured for packaging the LED chip, the first package including a flat first surface, and a second package including a second surface opposing the first surface. A micro-structure is defined in the second surface and protruding toward the first surface. A gap is maintained between the first and second surfaces. The gap is filled with a filler, and the refractive index of the filler is smaller than that of the first and second packages. Light generated by the LED chip radiates first through the first package, then the gap and the micro-structure, thereafter the second package to finally reach an outside of the LED. A light module including the LED is also provided.

BACKGROUND

1. Technical Field

The present disclosure relates to light emitting diodes (LEDs), and to a light source having the LEDs.

2. Description of Related Art

The maximum radiation angle of an LED is not 180°, so a number of LEDs aligned in a line to emit light yield a number of shadows corresponding to the gaps between adjacent LEDs. These shadows ruin the uniformity of the light field produced by the number of LEDs.

What is needed, therefore, is an LED and a light module having the LED, which can overcome the above shortcomings.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present LED and light module having the LED can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present LED and light module. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the views.

FIG. 1 is a cross-sectional view of an LED in accordance with a first exemplary embodiment.

FIG. 2 is a cross-sectional view of the LED of FIG. 1, taken along line II-II, showing a micro-structure defined in the second surface of the second package.

FIG. 3 is similar to FIG. 2 but shows another micro-structure defined in the second surface.

FIG. 4 is a cross-sectional view of an LED in accordance with a second embodiment.

FIG. 5 is a light source incorporating a plurality of LEDs each being formed in accordance with the first embodiment of FIG. 1 or the second embodiment of FIG. 4.

FIG. 6 is a cross-sectional view of an LED in accordance with a third embodiment.

DETAILED DESCRIPTION

Referring to the FIGS. 1 and 2, an LED 10 in accordance with a first embodiment includes an LED chip 12, a first package 14, and a second package 18. The first package 14 is configured to encapsulate the LED chip 12. The first package 14 includes a flat first surface 140. The first surface 140 is the light emitting surface of the LED chip 12. Light beams emitted by the LED chip 12 pass through the first package 14. The second package 18 packages the first package 14. The LED chip 12 is located on a support surface 160. Conductive wires 120 coupled to the LED chip 12 are electrically connected with lead frames 121.

The second package 18 includes a second surface 180 opposing the first surface 140. A micro-structure 20 protruding toward the first surface 140 is defined in the second surface 180. It can also be viewed as the micro-structure 20 falling inward to the second surface 180. A gap 21 is maintained between the first and second surfaces 140 and 180. The gap 21 can be a vacuum or can be filled with filler (not labeled). The refractive index of the filler is smaller than that of the first and second packages 14 and 18. The filler, in this embodiment, is air. The filler may be other gas or liquid.

The micro-structure 20 includes a number of V-shaped protrusions 200 (see FIG. 2) parallel to each other. The V-shaped portions 200 each have a pointed end (not labeled) in the shape of a line. The V-shaped protrusions 200 are connected to each other without gaps between them, or have a predetermined distance between two adjacent V-shaped protrusions 200. Each pointed end is near to the first surface 140 as shown in FIG. 1. Alternatively, each pointed end can be in contact with the first surface 140. The micro-structure 20 may consist of a number of cones 202 (see FIG. 3) or other protrusions. The number of cones 202 is uniformly distributed on the second surface 180. The cones 202 may connect to each other, or be separated from each as the FIG. 3 shows. The cones each have a peak (not labeled). Each peak is near to or in contact with the first surface 140.

The first package 14 may be any one of a number of transparent materials such as, epoxy resin, silicone resin, or glass. The second package 18 may be any one of a number of transparent materials such as, epoxy resin, silicone resin, and glass. The first package 14 includes phosphors (not shown) configured to change the color of light beams into a different color.

The micro-structure 20 is not in contact with the first surface 140, or only the tapered end of the micro-structure 20 is in contact with the first surface 140. The light beams of this embodiment first enter an optically thinner medium (the air in the gap 210) from an optically denser medium (the first package 14), and then enter another optically denser medium (the second package 18), the radiation angle is larger. Furthermore, the micro-structure 20 allows the light beams enter the first package 18 at a bigger refraction angle.

Referring to FIG. 4, an LED 30 provided by a second embodiment is similar to the LED 10. The main difference between the LEDs 30 and 10 is that a bottom end of the micro-structure 31 contacts the first surface 34. The micro-structure 31 is defined in and protrudes outward from the second surface 380. A gap 33 is maintained between the second surface 380 and the first surface 34. The gap 33 also exists between two adjacent V-shaped protrusions.

Referring to FIG. 5, a light module 50 in accordance with the present disclosure is shown which includes a light guide plate 52. A light incident surface 520 is defined in one side of the light guide plate 52. A number of the LEDs 10 is arranged adjacent to the light incident surface 520. The LEDs 10 are aligned along a line substantially parallel to the light incident surface 520. The LEDs 10 have larger radiation angles. The light module 50 therefore has a more uniform optical field with smaller or no shadow areas. The light incident surface 520 is a flat surface, and may be distributed with micro-structures to raise the uniformity of the optical field. The LED 10 can be replaced by the LED 30.

Referring to FIG. 6, an LED 60 of a third embodiment is provided. The LED 60 is similar to the LED 10. The main difference between them is that the outer surface 600 of the LED 60 is a flat surface, whereas the LED 10 has a curved outer surface. The LED 60 is more compact, whereas the LED 10 has a larger radiating range.

The LED 60 includes an LED chip 61, a first package 62, and a second package 63. The first package 62 is configured to package the LED chip 61. The first package 62 has a flat first surface 620. The second package 63 has a second surface 630 opposing the first surface 620. A micro-structure 631 defined in the second surface 630 protrudes toward the first surface 620. A gap 64 is maintained between the first surface 620 and the second surface 630. A refractive index of a filler (not shown) filling in the gap 64 is smaller than that of the first package and the second packages 62 and 63. The filler may be any one of a number of materials such as, air, water, or other gas, or other liquid. The filler is air in this embodiment.

The second package 63 is located over the first surface 620, and contacts the first surface 620 with a bottom end of the micro-structure 631 touching the first surface 620. The second package 63 may also completely encapsulate the first package 62. The second package 63 is a flat plate. The second package 63 is made of epoxy resin.

Traditionally, the light beams directly enter the second package 63 from the first package 62; in this embodiment the light beams first enter an optically thinner medium (the air in the gap 64) from an optically denser medium (the first package 62), and then enter another optically denser medium (the second package 63), the radiation angle is larger. Furthermore, the micro-structure 631 allows the light beams to enter the second package 63 at a larger refraction angle.

The LEDs provided by the embodiments may package only one LED chip inside or more than one.

It is understood that the above-described embodiments are intended to illustrate rather than limit the disclosure. Variations may be made to the embodiments without departing from the spirit of the disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure. 

1. An LED, comprising: an LED chip; a first package configured for packaging the LED chip, the first package comprising a flat first surface; and a second package comprising a second surface opposing the first surface, wherein a micro-structure is defined in the second surface and protruding toward the first surface, a gap is maintained between the first and second surfaces, the gap is filled with a filler, wherein a refractive index of the filler is smaller than that of the first and second packages, light generated by the LED chip radiating first through the first package, then the gap and the micro-structure, thereafter the second package to finally reach an outside of the LED.
 2. The LED according to claim 1, wherein the micro-structure comprises a plurality of V-shaped protrusions parallel to each other, each of the plurality of the V-shaped protrusions comprises a pointed end in a shape of a line, and the pointed end is in contact with the first surface.
 3. The LED according to claim 1, wherein the micro-structure comprises a plurality of V-shaped protrusions parallel to each other, each of the plurality of the V-shaped protrusions comprising a pointed end in a shape of a line, and the pointed end is near to the first surface.
 4. The LED according to claim 1, wherein the micro-structure comprises a plurality of cones, each of the plurality of the cones comprises a peak, and the peak is in contact with the first surface.
 5. The LED according to claim 1, wherein the micro-structure comprises a plurality of cones, each of the plurality of the cones comprises a peak, and the peak is near to the first surface.
 6. The LED according to claim 1, wherein the second package encapsulates the first package, an outer surface of the second package is a curved surface.
 7. The LED according to claim 1, wherein the second package lies on the first package, an outer surface of the second package is a flat surface.
 8. The LED according to claim 1, wherein the filler is the air.
 9. The LED according to claim 1, further comprising phosphors scattered in the first package to change the color of the light beams into a different color.
 10. A light source, comprising: a light guiding plate comprising a light incident surface; and a plurality of LEDs arranged adjacent to the light incident surface, each LED comprising: an LED chip; a first package configured for packaging the LED chip, the first package comprising a flat first surface; and a second package comprising a second surface opposing the first surface, wherein a micro-structure is defined in the second surface and protruding toward the first surface, a gap is maintained between the first and second surfaces, the gap is filled with a filler, wherein the refractive index of the filler is smaller than that of the first and second packages, light generated by the LED chip radiating first through the first package, then the gap and the micro-structure, thereafter the second package to finally reach the light guiding plate via the light incident surface.
 11. The light source according to claim 10, wherein the plurality of LEDs are aligned in a line substantially parallel to the light incident surface.
 12. The light source according to claim 10, wherein the micro-structure comprises a plurality of V-shaped protrusions parallel to each other, each of the plurality of the V-shaped protrusions comprises a pointed end in a shape of a line, and the pointed end is in contact with the first surface.
 13. The light source according to claim 10, wherein the micro-structure comprises a plurality of V-shaped protrusions parallel to each other, each of the plurality of the V-shaped protrusions comprising a pointed end in a shape of a line, and the pointed end is near to the first surface.
 14. The light source according to claim 10, wherein the micro-structure comprises a plurality of cones, each of the plurality of the cones comprises a peak, and the peak is in contact with the first surface.
 15. The light source according to claim 10, wherein the micro-structure comprises a plurality of cones, each of the plurality of the cones comprises a peak, and the peak is near to the first surface.
 16. The light source according to claim 10, wherein the second package encapsulates the first package, an outer surface of the second package is a curved surface.
 17. The light source according to claim 10, wherein the second package lies on the first package, an outer surface of the second package is a flat surface.
 18. The light source according to claim 10, wherein the filler is the air.
 19. The light source according to claim 10, further comprising phosphors scattered in the first package to change the color of the light beams into a different color.
 20. An LED, comprising: an LED chip; a first package configured for packaging the LED chip, the first package comprising a light emitting surface; a second package covering the first package; and a gap filled with air maintained between the light emitting surface and the second package; wherein light beams emitted from the light emitting surface pass through the gap and the second package to an outside of the LED. 